Section 27-668. Soil bearing pressures

The loads to be used in computing the
  bearing pressures on materials directly underlying footings shall be the
  total  column, pier, or wall reactions determined in accordance with the
  provisions of subchapter nine of this chapter, on the basis  of  reduced
  live  load;  plus  the weight of the foundations; plus the weight of any
  soil, fill, and slabs on grade that is included within  vertical  planes
  projected  upward  from  the  extreme limits of the footing to the final
  ground surface. Live load on grade, or on slabs on grade,  within  these
  limits  shall  also  be  included.  Impact  loads shall be considered in
  accordance with the provisions of section 27-673 of this article.